Nearly three months after Hurricane Katrina struck, scores of rescue and recovery workers -- from the Red Cross and other relief groups, FEMA and private industry -- remain in New Orleans, helping the devastated city get back to some version of normal.

Their numbers include the Columbia University-sponsored "Operation Assist," a joint initiative of the Mailman School of Public Health and the Children's Health Fund (CHF).

The operation, which was launched in the immediate wake of Hurricane Katrina to provide emergency health services for victims, is housed in two Mobile Medical Units (MMUs). Each MMU is a 35-foot-long RV containing two examination rooms and a nurse's station, as well as waiting and registration areas. The units come fully equipped with medicine and diagnostic equipment, computers, satellite and standard communications, and power generators.

On a sunny afternoon in New Orleans last month, a visit to one of these remarkable clinics-on-wheels revealed three doctors and two nurses, from CHF and Tulane University Medical Center, hard at work treating some 60–70 patients.

The team had been at it since one week after the hurricane, when the unit was driven south from Idaho to dispense emergency medical services.

Having been all over southeastern Louisiana, this particular MMU is now stationed at a FEMA disaster-assistance site in a vacated parking lot at a shopping center in western New Orleans.

In the beginning, the team was treating upper respiratory illnesses from irritants stirred up by the storm. Traumatic injuries, lacerations, and back and knee pain were also common.

Now, however, the unit spends most of its time returning patients to their regular medications. "We've shifted from disaster response to community medicine," said team leader Michael Duffy, a family physician from Twin Falls, Idaho. "We're meeting emergency needs, getting patients back on their meds, so that we can eventually turn over operations to Tulane [ University Medical Center]."

Most of the team's current patients are hard pressed to find medical attention with the closure of so many local doctors' offices, as well as several major New Orleans hospitals, Duffy explained. "There are a lot of displaced physicians, just as there are a lot of displaced residents," he said.

How does the team know whom to target? According to Duffy, "That's the largest obstacle in doing what we do, just finding out where the need is. You have to be a part-time private investigator … and word of mouth is the best tool for us."

Operation Assist will press on for at least several more weeks, focusing on locations where resources are limited and need is greatest -- particularly as residents return to the city and schools reopen.